4. A shop has a computerised stock control system. The sys…
4. A shop has a computerised stock control system. The system records the number of items the shop has in stock. When a customer buys an item, the number in stock is reduced. When a delivery of new stock arrives, the number of each item in stock is increased. 4a Explain how radio-frequency identification (RFID) tags can be used in the stock control system. (6) 4b The stock control system is set up as a client-server model. 4b (i) Describe the function of a client. (1) 4b (ii) Describe the function of a server. (1) 4b (iii) How does a peer-peer network model differ from a client-server model. (3) 4c Workers in the stock control room have handheld devices that they can use to scan items and access data on the server. Analyse and recommend an appropriate network communications protocol for connecting the portable handheld devices to the server. (5) 4c The network uses a range of network hardware components. 4c (i) Describe the function of a switch in a network. (2) 4c (ii) Describe the function of a repeater in a network. (2) 4c (iii) Name and describe a network hardware component that could be included in the network, other than a switch, repeater or server. (2) 4d The shop needs to protect the security of the data on its network and server. Data transferred on the network is always encrypted. Explain how encryption can help protect the security of the network. (2)